Internal-combustion engine



AUS- l2, 1930- T J. A. H. BARKEIJ 1,773,072

INTERNAL COMBUSTION ENGINE Filed Feb. l5, 1928 8a KL- F1c1, 1"` 4. E4 /1 8 /1 I l l 5 6 i 7 11 1o 9x 5.2, S2 l n, L/ Ta'\\, Ia "a\ Z 5dA 5c Fic 2 s, WM

'45 section line S2 Patented Aug. 12, 1930 UNITED STATES PATENT OFFICE INTERNAL-COMBUSTION ENGINE Application led February 15, 1928. Serial No. 254,543.

It is well known that internal combustion engines provided with a Ricardo head are subject to three serious drawbacks, 1, poor volumetric eiciency, 2, detonation, 3, plston slap due to pressure on one side of the piston. The second drawback is however present more or less in any type.

The iirst drawback is due to the throat between cylinder and combustion chamber and in an L-head construction this draw back is increased as the gases have t0 make a double curve to reach the cylinder space beyond the throat.

The real nature of detonation is still shrouded in mystery. Several theories have been proposed, each of which might contain some of the truth. The only practical fact known with certainty is that detonation is more liable to occur in a great volume of gas than in a small volume and for that reason the compression in smallengines can be appreciably higher than in big engines.

It is the first object of this invention to 'nnprove the volumetric efficiency by placing the inlet valve in the combustion space in the head and inverted, partially overlapping the cylinderbore. The double curve which the gas has to make in an L-head construction being eliminated, thereby increasing the volunletric eiciency of the engine, with an equal valve area, appreciably. The second object is to vretain the turbulence efect created by the throat and by the squeezing effect between the head and the piston, but to decrease the tendency of detonation by splitting up the combustion space in two smaller spaces entirely separated from each other.

Fig. 1 shows a sectional View on the vertical section line S1 in Fig. 2 of a cylinder, and cylinderhead, having an exhaust passage and valve in the left combustion chamber, and an inlet valve and passage to the right combustion chamber.

Fig. 2 is a sectional view on the horizontal of Fig. 1, showing the same parts.

, Fig. 3 is a sectional view on the same horizontal section line S2 of Fig. 1 of the same parts, when the valves are placed in the cylinder instead of in the head as in Fig. 1.

Fig. 4 is a horizontal section view on a section line S2, lower than that shown as Sz in Fig. 1, of a modied arrangement, where one exhaust valve is placed in the cylinderblock, andthe inverted inlet valve in the head at opposite sides of the piston, in order to form again two separate combustion chambers.

Fig. 5 is a vertical sectional view on two sectional lines, parallel to each other, like S1 in Fi 2, modiication of Fig. 1, the valves 60 being p aced at an angle in the head in two separate transverse planes in order to operate them with diiferent cams on the same overhead camshaft.

Fig. 6 shows Fig. 5 on the horizontal sec- 65 tion line S2.

Fig. 7 shows the arrangement for the L- head motor on a horizontal sectional line S2 similar to S2 in Fig. 1, but lower through an L-head with two combustion chambers, lying over the cylinderbore 3 and the valves 9 and 5, an inlet and an exhaust valve.

In all figures, 1 is the head, the undersurface 1a of which cooperates with the upper surface 3al of the piston 3 to create a turbu- 75 lence in both chambers and to establish two separate combustion chambers with two separate sparkplugs. 2 is the cylinder, 4 is the exhaust valve, 4 the exhaust passage, 5 the sparkplug for the exhaust combustion chamber to be discerned in a space 6 above the cylinderblock, and a space 7 above the piston.

8 is the inlet valve, 8a the inlet passage, both of greater diameter than those for the ex'- haust, as usual; 9 the sparkplug for this ing5 let combustion chamber, which can again be divided in a space over the cylinder 10 and a space over the cylinderbore 11.

The cycle of operation for. this arrangement is as follows: The exhaustgases are pushed by the piston thru the throat 7 past the exhaust valve 4 into the atmosphere. After the exhaust valve closes, the inlet gases pass the valve 8, the throat 11a into the cylinderspace 3. From Fig. 1 can be seen, that 95 the fresh gases pass practically 1n a straight line from the lnlet valve in the cylinder, which` circumstance eliminates so much wiredrawing, that the volumetric efficiency is very much increased especially a't high speeds. 100

, mum clearance, however, has to fi -The inlet valve closes, the piston comes up,

the gases are pushed thru the two throats in the two combustion chambers during the entire compression riod and cause thereby already an appreca le turbulence. This turbulence is at the ve last moment suddenly increased by the wel known squeezing effect of the Ricardo head. The upper surface 3 of the piston cooperates with the undersurface 1 of the head to establish further two separate combustion chambers. This minire on wear in the wrist in connecting rod caring, crankpin, cranks aft bearings, and )ournal pins and it is not advisable to decreasethis distance much more than to 31, inch. The sparks ass simultaneousl over the two points o the two plugs an the areas 7 and 11* being about the same, the explosion pressure will not tip the piston in thelcylinder and not cause that well known peculiar noise. The saine balance is in this way established as in the balancedressure arrangement, shown in my application No. 238,587 of Dec. 8, 1927, fora single combustion chamber having more or less the form of a horse shoe. The cycle is completed.

Let us consider what exactly happens with the gas condition in the two chambers. After the exhaust closes in the left chamber, the

.pressure will be here less than in the right chamber o'n account of the. piston and head forming a barrier between the two, during the last part of the exhaust. With little as, the inlet will sweep the right com ustion chamber clean, but not the left exhaust chamber and misfring in this chamber is liable to happen'. Increasing the amount of gas the ratio between the volume of burnt and fresh gases will adually approach an average, which will le the same for both chambers. The period of explosion with an extremely weak or rich mixture will be so lon that the burning is still progressing when t e piston and head are atA a distance considerably greater than the clearance space, but with a normal air-fuel ratio the burning takes virtually place in two separate chambers. The volume being small, the explosion eriod being smaller than for the total vo ume in a single combustion space. A higher compression can therefore be used without the danger of detonation.

The throat 11 is made wider than the throat 7 as it is, of course, easier to ush the gases out than to introduce them in t e cyliner under atmospheric pressure. Normally bot-h throats are considered to have an area slightly in excess to the areas of the res ective inletl and exhaust valves. If a superc arger is used they may be respectively smaller in this sense that the ratios for both may be different. The inlet throat and inlet valve area is by the supercharging more affected than the exhaust throat and exhaust valve area.

If a supercharger, a Roots blower or centrifu al type, is used the valves can be made smallr and also the throats. Without a blower the throat 11 has to be larger than the inlet valve area. For the exhaust this `is not so necessary. The smaller the throats are, the greater are the squeezing surfaces of the head and piston and the more turbulence will be caused in the `two chambers. The valves can be operated from a single camshaft in the crankcase by means of rocker arms, as is well known.

The dotted lines 6 and 10|` in Figs. 2 and 3 show that the combustion spaces can beconsiderably decreased if desired, which becomes of prime importance alread for bores of about 3 inches, as shown. he valves are shown with a minimum size for this bore.

Figs. 1, 2, 3, 5 show that the chamber with the inlet valve has a greater volume than that with the exhaust valve. This is not an absolute necessary feature of construction, but if the compression is carried up very high with special fuel (benzol, alcohol or' mixture of gasoline and said fuels) the available coni-rv pression space is ve small and the size of the valves determine indirectly the size of the chamber.

The valves can be placed of course in the cylinder and a top view only of this arrangement is shown in Fig. 3 (compare Fig. 3 with Fig. 2) to illustrate clearly the considerable difference in the minimum volumes of the two chambers in the two constructions. In the L-liead construction the chambers must be comparatively very shallow on account of their length. The overall Width of the head and top part of the cylinder is excessive, com pared with that of Fig. 2 and re resents almost a difference of Clinsiderable weight, material and labor is saved and a compact engine with clean lines can be construct(- ed on the basis of Fig. 1 and Fig. 2.

Fig. 4 shows that the exhaust valve 4 can be placed in the cylinderblock and the inverted inlet valve 8 in the head overlapping the cylinderbore as in Fig. 1. The latter valve can be operated from the same camshaft in the crankcase by a rockerarm. The two combustion chambers are again separated by the space of near-contact between piston and head 3" as shown shaded.

Figs. 5 and 6 shows that the valves, if placed in the head can be very conveniently and directly operated by a single overheadcamshaft. The valves are placed in two different transverse planes to be operated by two different cams on the shaft. The combustion chambers can be made as com act as shown in Fig. 1. It is understood t at the inverted inlet valve 8 of Fig. 4 can be equalg" placed at an angle as the inlet valve 8 of 1g. 5, and can be equally operated from a single camshaft.

Fig. 7 shows diagrammatically that the same arrangement of two combustion chambers in the cylinderhead can be applied, mu-

tatis mutandis, on an L-head construction, having both valves in the cylinder on the same side, instead of on opposite sides. This type is an extreme form or a continuation of the horseshoe type shown and discussed in my application No. 238,587, of Dec. 8, 1927 and that of Figs. 6-9 of my application No. 253,594, tiled Febr. 11, 1928. The undersurface of the head 1a is extended between the two valves, creating thereby two separate chambers, each chamber having one valve and one sparkplug. This arrangement however makes the unit of one cylinder and two valves rather broad and is favorable only for large 4 cylinder truck engines. A six cylinder would be rather long. Particularly is the attentionv drawn to the semicircle shape of the combustion chambers of Fig. 2. The ame 'propagating from the sparkplugs are supposed to spread at equal speed in all directions to the opposite walls, shown in a half circle. The particular phenomena experienced with this type of form of chamber is'somehow connected with the socalled detonation of the fuel.

I claim:

1. An internal combustion engine of the fourcycle type, including cylinder, piston and cylinderhead formed with separate 1nlet and exhaust valve chambers, separated from each other by wide areas of small clearance between cylinderhead and piston, when the latter is at the end of its compression stroke, the inlet chamber aording most of the compression space, while the exhaust chamber is smaller than the inlet chamber, in combination with a spark plug in said inlet chamber, and one in said exhaust chamber.

2. An internal combustion engine of the -fourcycle type, including cylinder, piston and cylinderhead formed with separate inlet and exhaust valve chambers separated from each other by Wide areas of small clearance between the cylinderhead and the piston when the latter is at the end of its compression stroke, the inlet chamber alfording most of the compression space, while the exhaust chamber is relatively small, in combination with separate spark plugs for each of said chambers.

8. An internal combustion engine of the fourcycle type, including cylinder, piston and cylinderhead formed with separate inlet and exhaust valve chambers, separated from each other by wide arcas of small clearance bctween cylinderhead and piston, when the latter is at the end ot its compression stroke, the inlet chamber overlapping the cylinderbore with an area greater than the overlapping of the exhaust chamber over said cylinder.

4. The combination of claim 1 in which 7 said chambers overlap said cylinderbore,

thereby forming throats between said chambers and said cylinderbore, said valves in said chambers having respectively an area smaller than said respective throats.

5. The combination of claim 3 in which the area of the inlet'valve is smaller than the area of the throat.

6. The combination of claim 3 in which the effective inlet area of said inlet valve passage is smaller than the eiective inlet area of said inlet throat between said cylinderbore and said inlet valve chamber.

7 The combination of claim 3, in which said valves are located in the head overlapping partially said cylinder-bore to increase the volumetric eiiciency of said engine and to decrease the volume of each combustion chamber.

8. The combination of claim 3, in which at least one of the combustion chambers has its valvular means located in thehead, said means yoverlapping the cylinderbore to increase the volumetric eliciency.

9. The combination of claim 3, in which at least one of said chambers, by preference the inlet chamber, has its valve overlapping the cylinderbore, said inlet valve having a greater capacity than said exhaust valve.

10. The combination of claim 3, in which said inlet and said exhaust valves have different effective areas, and have diferent effective ratios between these areas; the respective restricted passages between these respective inlet and exhaust valve chambers having also different areas.

11. The combination of claim 3, in which the respective valves of said chambers have different areas, the inlet valve being larger than the exhaust valve.

12. An internal combustion engine, having at least one combustion chamber in restricted communication with a cylinder, in which a piston reciprocates, valvular means in said chamber and spark ignition means in said chamber, said latter means arranged perpendicularly to the axis of said cylinder in a Wall of said chamber, having substantially a straight surface; opposite said ignition means a wall, having substantially a Semicircular form, all of said points in said latter wall being substantially at an equal distance from said spark ignition means.

13. The combination of claim 12 in an engine, in which said piston and said cylinderhead form a separate inlet and exhaust valve chamber, separated from each other by wide areas of small clearance between cylinderhead and piston, the inlet chamber at'- fording most of the compression space, while the exhaust chamber is smaller than the inlet chamber, in combination with a sparkplug in said inlet chamber, and one in said exhaust chamber; each of said chambers having substantially the form and shape defined in said claim.

14. The combination of claim 12in which said piston and said cylinderhead form separate mlet and exhaust valve chambers, separated from each other by Wide areas of small clearance between cylinderhead and piston, when the latter is at the end of the compression stroke; the inlet chamber overlapping the cylinderbore with an area greater than the overlapping of the exhaust chamber over said cylinder; each of said chambers having substantially the form and shape delined in said claim.

15. An internal combustion engine, having a cylinder, a piston reciprocating in said cylinder, a combustion chamber adjoining and communicating restrictedly with the end of said cylinder, said lcombustion chamber being entirely located in said cylinderhead when the piston is in the position of greatest compression, an inlet valve in said combustion chamber in inverted position overlapping the cylinderbore of said cylinder to facilitate the ow of gases from the atmosphere into said cylinder, said restricted communication formed at one side of said bore by the undersurface of said'head and upper surface of said cylinder.

16. An internal combustion engine, having a cylinder, a. piston reciprocating in said cylinder, at least one combustion chamber overlapping the cylinderbore nf .mid cylinder, a throat between said combustion space and said cylinderbore, an inverted valve in said combustion chamber partially overlapping said cylinderbore facilitating thereby the flow of gases between said valve and said cylinderbore through said throat, said combustion chamber being entirely located beyond said throat in said cylinderhead, when said piston in the position of greatest compression, said throat formed at one side of said bore by said head and cylinder.

17. The combination of claim 16 in which said valve is an inlet valve, said valve overlappin said throat in order to facilitate the flow o gases from the atmosphere into said cylinder.

18. An internal combustion engine having a cylinder, a piston reciprocating in sai cyllnder, an exhaust valve and an 1nlet valve at least one of said valves 1n inverted pos1- tion overlapping said cylinderbore above a throat between said cylinderbore and a combustion space partiall overlapping said cylinderbore; said com ustion space entirely located in a cylinderhead, closing the open end of said cylinder, when said piston is in said head above one of said restricted passages and overlapping said cylinderbore to facilitate the flow of gas from the atmosphere into said cylinder; separate sparkplugs for each of said chambers,

J. A. H. BARKEIJ.

the position of greatest compression; said combustion space containing said inverted valve above said throat.

19. An internal combustion engine, having a. cylinder, a piston reciprocating in said cylinder, a cylinderhead arranged to afford a plurality of compression chambers, each chamber having at least one valve in in- 

